1. Field of the Invention
The invention relates to a method of repairing organic light-emitting element pixels, and in particular, to a method of repairing an organic light-emitting element having a substantial short circuit portion or substantial short circuit portions.
2. Description of the Related Art
In the manufacture of organic light-emitting element, a photolithography process is performed to define an anode and an auxiliary anode, and a process for forming organic and inorganic materials in a vacuum chamber is then performed. Herein, the inorganic material is used for forming a cathode layer. Since environmental factors such as moisture and oxygen may influence the lifetime of the organic light-emitting element, the organic light-emitting element must be encapsulated so as to maintain normal element operation.
During the manufacturing processes of the organic light-emitting element, the insufficient cleanliness in the clean room or the substrate defects may cause a short circuit in the organic light-emitting element. Moreover, electric current may only pass through the defects of the light-emitting element, such that not all of the pixels can be driven. Thus, inhibiting the light emitting efficiency of the element and reducing image display quality. Furthermore, if the organic light-emitting element is driven passively, not only is a single pixel not able to emit light, but an entire column or a row of pixels may be disabled.
Referring to FIG. 1, a conventional method of testing an organic light-emitting element for defects is to perform a panel testing step (S22) subsequent to an encapsulating step (S21). If the organic light-emitting element has a short circuit portion or short circuit portions, the defects in the individual pixels inside the element cannot be repaired as the element has already been encapsulated. Thus, the encapsulated element must be totally discarded. Accordingly, product yield decreases and manufacturing cost increases.
It is therefore an objective of the invention to provide a method of repairing organic light-emitting element defects, which is capable of reducing manufacturing cost, and increasing product yield and reliability.
To achieve the above-mentioned objective, the invention provides a method of repairing organic light-emitting element defects. The organic light-emitting element includes an anode substrate, an organic functional layer and a cathode, and has a substantial short circuit portion or substantial short circuit portions. The method includes an electrical testing step and an insulator-forming step. In the electrical testing step, a current or voltage is applied to the anode substrate and the cathode of the organic light-emitting element respectively, so that the short circuit portion or portions of the organic light-emitting element can be changed to an open circuit portion or portions. In the insulator-forming step, an insulator is formed at the open circuit portion or portions of the organic light-emitting element. The invention also provides a method of repairing organic light-emitting element pixels, which further includes an electrical detection step. In the electrical detection step, a short-circuited level of the organic light-emitting element is detected. Specifically, when the ratio of the amount of short circuit portions to the amount of open circuit portions is smaller than a predetermined value, or a leakage current is smaller than a predetermined value, an insulator is formed on the open circuit portion or portions in the subsequent insulator-forming step.
The invention provides a method of repairing organic light-emitting element pixels, which is used to repair the substantial short circuit portion or portions in the organic light-emitting element. The method is capable of detecting and repairing the short circuit portion or portions before the encapsulation process is performed. The method causes the short circuit portions to lose their electro conductivity, and enables the pixels with defects to have the same light-emitting ability as properly functioning adjacent pixels without defects. The method of the invention repairs the organic light-emitting element having defective portions without discarding the entire panel, thereby reducing manufacturing cost and increasing product yield and reliability.